How to calculate radiance emitted?

How to calculate radiance emitted?

Science

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Upward Spiral

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Originally posted by KazetNagorra
I don't see the conflict - if you regard a black body at t = 0 and wait for a photon to be emitted at exactly 744 nm it won't happen. The wavelength of an emitted photon will contain an infinite string of random numbers in decimal representation and even though the infinite string of all zeros is not any less likely than any other particular infinite st ...[text shortened]... safe to say a black body will never emit a 744 nm photon (or "almost sure", if you insist).
The conflict is that adam's statement was perfectly correct and precise.

Your corrections are therefore out of place and, worse, are more imprecise with the wording.

It's false to say that events of probability zero won't happen. It's as simple as that. In fact, all future wavelength emissions have probability zero of happening, yet they will happen.

aw
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1 edit

Originally posted by KazetNagorra
You don't analyze the case L = 0, since that doesn't allow any EM mode. You start with some finite L, which allows wavenumbers (in 1D, generalization to 3D is straightforward) k = 2*pi*n/L with n integer. Taking the limit of L to infinity allows a continuum integral formulation appropiate for thermodynamics, and allows photons will arbitrarily low energies instead of the lower limit corresponding to k = 2*pi/L in the finite L case.
Shame on me for writing L=0. But good thing you understand what I meant.

By the way: wrong answer.

Read up on probability theory, statistical mechanics, and quantum mechanics. 😉

K

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Originally posted by adam warlock
Shame on me for writing L=0. But good thing you understand what I meant.

By the way. wrong answer.

Read up on probability theory, statistical mechanics, and quantum mechanics. 😉
I will, for the next five years or so.

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Baby Gauss

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Originally posted by KazetNagorra
I will, for the next five years or so.
How long is your degree? Or are you already counting with a future Masters/PhD ?

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Originally posted by adam warlock
How long is your degree? Or are you already counting with a future Masters/PhD ?
I am currently getting my master's degree and intend to get a PhD position.

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Originally posted by KazetNagorra
I am currently getting my master's degree and intend to get a PhD position.
In this case you really need to, at least, study those things.

I mean if you want to be a PhD in physics and can't even interpret probabilities you really need a lot of catching up to do.

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Originally posted by adam warlock
In this case you really need to, at least, study those things.

I mean if you want to be a PhD in physics and can't even interpret probabilities you really need a lot of catching up to do.
Maybe.

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There has been a sub-discussion in this thread about probability zero. On argument states that "events of probability zero may happen". If find this impossible.

An event that has probability zero cannot happen!

If p=0 can happen, than anything can happen.
The probability that the sun is gone and been gone from the time Earth was into being has zero probability. It's there, we see it, we can measure it, th whole life on earth is dependant that it's there. If someone says that even if the probability is zero that it's gone, it might be that the suns is gone, I will object.
If the probability that the sun is gone tomorrow, is zero, then it will surely be there tomorrow. If it's even the slightest is > zero, then it might be gon tomorrow, but when b=0, and exactly =0, then it will be there tomorrrow too, rely on that.
If we calculate that the probability of that the sun is gone tomorrow is exactly zero, and it actually isn't there tomorrow, then we have made an error in our calculation.

Bottom line: An event that has probability zero cannot happen!

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Originally posted by FabianFnas
There has been a sub-discussion in this thread about probability zero. On argument states that "events of probability zero may happen". If find this impossible.

An event that has probability zero cannot happen!

If p=0 can happen, than anything can happen.
The probability that the sun is gone and been gone from the time Earth was into being has zer ...[text shortened]... ror in our calculation.

Bottom line: An event that has probability zero cannot happen!
Physicists these days don't seem to understand anything of probability theory.

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1 edit

Let's do a basic exercise, shall we?

Take a normal distribution, what is the probability that you draw any individual real number x?

Edit - Let's label this probability P(X=x)

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Originally posted by Palynka
Let's do a basic exercise, shall we?

Take a normal distribution, what is the probability that you draw any individual real number x?

Edit - Let's label this probability P(X=x)
You tell me, you are arguing your line, you tell me.

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Originally posted by FabianFnas
You tell me, you are arguing your line, you tell me.
P(X=x) = 0 for all x in the set of all reals. Do you agree, Mr. "Physicist"?

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I wonder how long will it take for Fabian to realize he's again wrong and start shrieking about being stalked.

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Originally posted by Palynka
Physicists these days don't seem to understand anything of probability theory.
Admittedly it's not my field of expertise. They don't teach it much.

aw
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2 edits

Originally posted by Palynka
Physicists these days don't seem to understand anything of probability theory.
😠

Kazet is a physicist to be and still has enough time to steer away from the dark side of the force.

Is Fabian a physicist? I predict that event to have a 0 probability. 😉

But the fact that Kazet, a physics student, has a very weak grasp of probability theory strike me as very odd.